Re: [PATCH v2 1/3] dmaengine: add DMA_PREP_CMD for non-Data descriptors.

From: Abhishek Sahu
Date: Wed Jul 19 2017 - 08:26:24 EST


On 2017-07-19 15:41, Vinod Koul wrote:
On Mon, Jul 17, 2017 at 02:54:21PM +0530, Abhishek Sahu wrote:
On 2017-06-26 18:19, Abhishek Sahu wrote:
>Some of the DMA controllers are capable of issuing the commands
>to peripheral by the DMA. These commands can be list of register
>reads/writes and its different from normal data reads/writes.
>This patch adds new flag DMA_PREP_CMD in DMA API which tells
>the driver that the data passed to DMA API is in command format
>and DMA driver will form descriptor in the required format.
>
>This flag can be used by any DMA controller driver which requires
>special handling for non-Data descriptors.
>
>Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx>
>---
> include/linux/dmaengine.h | 3 +++
> 1 file changed, 3 insertions(+)
>
>diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
>index 5336808..bbc297e 100644
>--- a/include/linux/dmaengine.h
>+++ b/include/linux/dmaengine.h
>@@ -186,6 +186,8 @@ struct dma_interleaved_template {
> * on the result of this operation
> * @DMA_CTRL_REUSE: client can reuse the descriptor and submit again till
> * cleared or freed
>+ * @DMA_PREP_CMD: tell the driver that the data passed to DMA API is in
>command
>+ * format and it will be used for configuring the peripheral registers.
> */
> enum dma_ctrl_flags {
> DMA_PREP_INTERRUPT = (1 << 0),
>@@ -195,6 +197,7 @@ enum dma_ctrl_flags {
> DMA_PREP_CONTINUE = (1 << 4),
> DMA_PREP_FENCE = (1 << 5),
> DMA_CTRL_REUSE = (1 << 6),
>+ DMA_PREP_CMD = (1 << 7),

Hi Vinod/Dan,

Could you please help in reviewing these DMA patches.
I have posted QPIC NAND support patches which are dependent
upon these DMA patches.

Please allow reasonable time for review! This patch series was sent just
before the merge window and it closed couple of days back!!


Sure Vinod and extremely sorry for my ping.

Since we are adding the flag in generic DMA engine and the complete
QPIC NAND support patch series dependent upon this so we were
bit concerned about this patch.


https://www.spinics.net/lists/kernel/msg2545386.html


> };
>
> /**


--
Abhishek Sahu